When onResume is called app throws ArrayIndexOutOfBouds

Question

When I click home button onPause method is called but when I call application in front onResume is called and than it crashes.

There is code when index is out of bouds:

while (isRunning) {
                if (!ourHolder.getSurface().isValid())
                    continue;

                Canvas canvas = ourHolder.lockCanvas();
                canvas.drawRGB(02, 02, 150);
                fingerx = (x - (Gball.getWidth() / 2));
                fingery = (y - (Gball.getHeight() * 2));
                for (int i = 0; i < balls.size(); i++) { // here...
                    ballX[i] = i * 155;
                    canvas.drawText("" + score, 40, 100, paint);
                    canvas.drawBitmap(balls.get(i), ballX[i], ChangingY[i],
                            null);

Error is:

FATAL EXCEPTION: Thread-9140
java.lang.ArrayIndexOutOfBoundsException: length=4; index=4
at com.example.mygame.GFXSurface$GameSurface.run(GFXSurface.java:199)
at java.lang.Thread.run(Thread.java:864)

I know index should be 5 here but if it is than application doesn't even start

OnResume:

@Override
protected void onResume() {
    // TODO Auto-generated method stub
    super.onResume();
    ourSurfaceView.resume();
}



public void resume() {
            isRunning = true;
            ourThread = new Thread(this);
            ourThread.start();
        }

Run method:

@Override
        public void run() {

            for (int j = 0; j < 4; j++) {
                balls.add(j, RandomBall());
            }
            Paint paint = new Paint();
            paint.setColor(Color.RED);
            paint.setTextSize(100);
            paint1.setStyle(Style.FILL);
            paint1.setColor(Color.RED);

            while (isRunning) {
                if (!ourHolder.getSurface().isValid())
                    continue;

                Canvas canvas = ourHolder.lockCanvas();
                canvas.drawRGB(02, 02, 150);
                fingerx = (x - (Gball.getWidth() / 2));
                fingery = (y - (Gball.getHeight() * 2));
                for (int i = 0; i < balls.size(); i++) {
                    ballX[i] = i * 155;
                    canvas.drawText("" + score, 40, 100, paint);
                    canvas.drawBitmap(balls.get(i), ballX[i], ChangingY[i],
                            null);
                    if (x != 0 && y != 0 && mode == 0) {
                        if (fingerx < 0) {
                            canvas.drawBitmap(Gball, 0, fingery, null);
                        } else if (fingery < 0) {
                            canvas.drawBitmap(Gball, fingerx, 0, null);
                        }
                        else
                            canvas.drawBitmap(Gball, fingerx, fingery, null);
                        checkForCollision(i);
                    }
                    if (ChangingY[i] <= canvas.getHeight()) {
                        ChangingY[i] += 1 * speed;
                    } else if (ChangingY[i] > canvas.getHeight()) {
                        ChangingY[i] = -72;
                        if (speed <= 11)
                            speed += 0.25;
                        removeAndAdd(this, i);

                    }
                }

                ourHolder.unlockCanvasAndPost(canvas);
            }
        }

Answer 1

You are looping based on the size of balls but within your loop you are accessing both ballX and ChangingY using the index i. If ballX is smaller than balls then you will get an ArrayIndexOutOfBoundsException.

Since you are updating the values within the array ballX during the loop, then you probably want to create a new array using the size of balls before the loop starts:

ballX = new int[balls.size()];

Don't know what ChangingY is, but you will need to make sure that is also at least as big as balls.